Method and apparatus for enabling concurrent transport via control plane

ABSTRACT

A method includes generating a payload container information element comprising two or more payload entries at user equipment in a communication system, and sending the payload container information element from the user equipment to at least one network element in the communication system. Another method includes receiving a payload container information element comprising two or more payload entries at a network function in a communication system from user equipment in the communication system, and decoding the two or more payload entries of the payload container information element into two or more individual payloads at the network function.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation of U.S. application Ser. No.16/696,544, filed Nov. 26, 2019, which claims priority to U.S.Provisional Application No. 62/774,113, filed Nov. 30, 2018, the entirecontents of which are incorporated herein by reference.

FIELD

The field relates generally to communication systems, and moreparticularly, but not exclusively, to data transport within suchsystems.

BACKGROUND

This section introduces aspects that may be helpful in facilitating abetter understanding of the inventions. Accordingly, the statements ofthis section are to be read in this light and are not to be understoodas admissions about what is in the prior art or what is not in the priorart.

Fourth generation (4G) wireless mobile telecommunications technology,also known as Long Term Evolution (LTE) technology, was designed toprovide high capacity mobile multimedia with high data ratesparticularly for human interaction. Next generation or fifth generation(5G) technology is intended to be used not only for human interaction,but also for machine type communications in so-called Internet of Things(IoT) networks.

While 5G networks are intended to enable massive IoT services (e.g.,very large numbers of limited capacity devices) and mission-critical IoTservices (e.g., requiring high reliability), improvements over legacymobile communication services are supported in the form of enhancedmobile broadband (eMBB) services providing improved wireless Internetaccess for mobile devices.

In an example communication system, user equipment (5G UE in a 5Gnetwork or, more broadly, a UE) such as a mobile terminal (subscriber)communicates over an air interface with a base station or access pointreferred to as a gNB in a 5G network. The access point (e.g., gNB) isillustratively part of an access network of the communication system.For example, in a 5G network, the access network is referred to as a 5GSystem and is described in 5G Technical Specification (TS) 23.501,V15.2.0, entitled “Technical Specification Group Services and SystemAspects; System Architecture for the 5G System,” the disclosure of whichis incorporated by reference herein in its entirety. In general, theaccess point (e.g., gNB) provides access for the UE to a core network(CN), which then provides access for the UE to other UEs and/or a datanetwork such as a packet data network (e.g., Internet).

TS 23.501 goes on to define a 5G Service-Based Architecture (SBA) whichmodels services as network functions (NFs) that communicate with eachother using representational state transfer application programminginterfaces (Restful APIs).

Furthermore, 5G Technical Specification (TS) 33.501, V15.1.0, entitled“Technical Specification Group Services and System Aspects; SecurityArchitecture and Procedures for the 5G System” and 5G Technical Report(TR) 33.899, V1.3.0, entitled Technical Specification Group Services andSystem Aspects; Study on the Security Aspects of the Next GenerationSystem,” the disclosures of which are incorporated by reference hereinin their entireties, further describe security management detailsassociated with a 5G network.

Security management is an important consideration in any communicationsystem. For example, protections in a 5G network against false basesstations, e.g., communication equipment or devices, operated bymalicious actors, pretending to be legitimate base stations in a servingnetwork, are critical to prevent such malicious actors from acquiringsensitive subscriber information that would allow them to, inter alia,act like a legitimate UE to the 5G network.

SUMMARY

Illustrative embodiments provide improved techniques for data transportin communication systems particularly with respect to enablingconcurrent transport via the control plane.

For example, in one illustrative embodiment, a method comprises thefollowing steps. A payload container information element comprising twoor more payload entries is generated at user equipment in acommunication system. The payload container information element is sentfrom the user equipment to at least one network element in thecommunication system. The user equipment is implemented via at least oneprocessor coupled to a memory.

In another illustrative embodiment, a method comprises the followingsteps. A payload container information element comprising two or morepayload entries is received at a network function in a communicationsystem from user equipment in the communication system. The two or morepayload entries of the payload container information element are decodedinto two or more individual payloads at the network function. Thenetwork element is implemented via at least one processor coupled to amemory.

In another illustrative embodiment, a method comprises the followingsteps. A payload container information element comprising two or morepayload entries is generated at a network element in a communicationsystem. The payload container information element is sent from thenetwork element to user equipment in the communication system. Thenetwork element is implemented via at least one processor coupled to amemory.

In another illustrative embodiment, a method comprises the followingsteps. A payload container information element comprising two or morepayload entries is received at user equipment in a communication systemfrom a network element in the communication system. The two or morepayload entries of the payload container information element is decodedinto two or more individual payloads at the user equipment. The userequipment is implemented via at least one processor coupled to a memory.

Further illustrative embodiments are provided in the form ofnon-transitory computer-readable storage medium having embodied thereinexecutable program code that when executed by a processor causes theprocessor to perform the above steps. Still further illustrativeembodiments comprise apparatus with a processor and a memory configuredto perform the above steps.

These and other features and advantages of embodiments described hereinwill become more apparent from the accompanying drawings and thefollowing detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a communication system with which one or moreillustrative embodiments are implemented.

FIG. 1 a illustrates a non-access stratum (NAS) message with multiplepayloads destined towards different network functions that is generatedby user equipment and sent to the network.

FIG. 1B illustrates that payloads from different network functions arebundled into a NAS message with multiple payloads and sent to the userequipment.

FIG. 2 illustrates user equipment and a base station configured forproviding data transport management with which one or more illustrativeembodiments are implemented.

FIG. 3 illustrates a user equipment-initiated transport procedure in anillustrative embodiment.

FIG. 4 illustrates a network-initiated transport procedure in anillustrative embodiment.

FIG. 5 illustrates a payload container information element in anillustrative embodiment.

FIG. 6 illustrates a payload container information element with apayload container type specifying multiple payloads in an illustrativeembodiment.

FIG. 7 illustrate a payload container entry in an illustrativeembodiment.

FIG. 8 illustrates an optional information element entry in anillustrative embodiment.

FIG. 9 illustrates a payload container information element in anillustrative embodiment.

DETAILED DESCRIPTION

Embodiments will be illustrated herein in conjunction with examplecommunication systems and associated techniques for providing datatransport in communication systems. It should be understood, however,that the scope of the claims is not limited to particular types ofcommunication systems and/or processes disclosed. Embodiments can beimplemented in a wide variety of other types of communication systems,using alternative processes and operations. For example, althoughillustrated in the context of wireless cellular systems utilizing 3^(rd)Generation Partnership Project (3GPP) system elements such as a 3GPPnext generation system (5G), the disclosed embodiments can be adapted ina straightforward manner to a variety of other types of communicationsystems.

In accordance with illustrative embodiments implemented in a 5Gcommunication system environment, one or more 3GPP technicalspecifications (TS) and technical reports (TR) provide furtherexplanation of user equipment and network elements/functions and/oroperations that interact with one or more illustrative embodiments,e.g., the above-referenced 3GPP TS 23.501, 3GPP TS 33.501, and 3GPP TR33.899. Other 3GPP TS/TR documents provide other conventional detailsthat one of ordinary skill in the art will realize. However, whileillustrative embodiments are well-suited for implementation associatedwith the above-mentioned 5G-related 3GPP standards, alternativeembodiments are not necessarily intended to be limited to any particularstandards.

Furthermore, illustrative embodiments will be explained herein in thecontext of the Open Systems Interconnection model (OSI model) which is amodel that conceptually characterizes communication functions of acommunication system such as, for example, a 5G network. The OSI modelis typically conceptualized as a hierarchical stack with a given layerserving the layer above and being served by the layer below. Typically,the OSI model comprises seven layers with the top layer of the stackbeing the application layer (layer 7) followed by the presentation layer(layer 6), the session layer (layer 5), the transport layer (layer 4),the network layer (layer 3), the data link layer (layer 2), and thephysical layer (layer 1). One of ordinary skill in the art willappreciate the functions and interworkings of the various layers and,thus, further details of each layer are not described herein. However,it is to be appreciated that while illustrative embodiments arewell-suited for implementations that utilize an OSI model, alternativeembodiments are not necessarily limited to any particular communicationfunction model.

Illustrative embodiments are related to security management associatedwith the Service-Based Architecture (SBA) for 5G networks. Prior todescribing such illustrative embodiments, a general description of maincomponents of a 5G network will be described below in the context ofFIGS. 1 and 2 .

FIG. 1 shows a communication system 100 within which illustrativeembodiments are implemented. It is to be understood that the elementsshown in communication system 100 are intended to represent mainfunctions provided within the system, e.g., UE access functions,mobility management functions, authentication functions, serving gatewayfunctions, etc. As such, the blocks shown in FIG. 1 reference specificelements in 5G networks that provide these main functions. However,other network elements are used in other embodiments to implement someor all of the main functions represented. Also, it is to be understoodthat not all functions of a 5G network are depicted in FIG. 1 . Rather,functions that facilitate an explanation of illustrative embodiments arerepresented. Subsequent figures depict some additionalelements/functions.

Accordingly, as shown, communication system 100 comprises user equipment(UE) 102 that communicates via an air interface 103 with an access point(e.g. gNB, eNB or N3IWF) 104. The UE 102 in some embodiments is a mobilestation, and such a mobile station may comprise, by way of example, amobile telephone, a computer, or any other type of communication device.The term “user equipment” as used herein is therefore intended to beconstrued broadly, so as to encompass a variety of different types ofmobile stations, subscriber stations or, more generally, communicationdevices, including examples such as a combination of a data cardinserted in a laptop or other equipment such as a smart phone or othercellular device. In one or more illustrative embodiments, user equipmentrefers to an IoT device and/or a device that executes ultra-reliable lowlatency communication (URLLC) application software where computingresources on the UE are limited or performance and timing requirementsare very stringent. Such communication devices are also intended toencompass devices commonly referred to as access terminals.

In one embodiment, UE 102 is comprised of a Universal Integrated CircuitCard (UICC) part and a Mobile Equipment (ME) part. The UICC is theuser-dependent part of the UE and contains at least one UniversalSubscriber Identity Module (USIM) and appropriate application software.The USIM securely stores the permanent subscription identifier and itsrelated key, which are used to identify and authenticate subscribers toaccess networks. The ME is the user-independent part of the UE andcontains terminal equipment (TE) functions and various mobiletermination (MT) functions.

Note that, in one example, the permanent subscription identifier is anInternational Mobile Subscriber Identity (IMSI) of a UE. In oneembodiment, the IMSI is a fixed 15-digit length and consists of a3-digit Mobile Country Code (MCC), a 3-digit Mobile Network Code (MNC),and a 9-digit Mobile Station Identification Number (MSIN). In a 5Gcommunication system, an IMSI is referred to as a Subscription PermanentIdentifier (SUPI). In the case of an IMSI as a SUPI, the MSIN providesthe subscriber identity. Thus, only the MSIN portion of the IMSItypically needs to be encrypted. The MNC and MCC portions of the IMSIprovide routing information, used by the serving network to route to thecorrect home network. When the MSIN of a SUPI is encrypted, it isreferred to as a Subscription Concealed Identifier (SUCI).

The access point 104 is illustratively part of an access network of thecommunication system 100. Such an access network comprises, for example,a 5G System having a plurality of base stations and one or moreassociated radio network control functions. The base stations and radionetwork control functions in some embodiments are logically separateentities, but in some embodiments are implemented in the same physicalnetwork element, such as, for example, a base station router or femtocellular access point.

The access point 104 in this illustrative embodiment is operativelycoupled to mobility management functions 106. In a 5G network, themobility management function is implemented by an Access and MobilityManagement Function (AMF). A Security Anchor Function (SEAF) in someembodiments is also implemented with the AMF connecting a UE with themobility management function. A mobility management function, as usedherein, is the element or function (i.e., entity) in the core network(CN) part of the communication system that manages or otherwiseparticipates in, among other network operations, access and mobility(including authentication/authorization) operations with the UE (throughthe access point 104). The AMF provides transport for messages betweenthe UE and other network functions, such as forwarding sessionmanagement (SM) messages between the UE and a session managementfunction (SMF), short message service (SMS) messages between the UE andthe SMS function (SMSF), Location Services messages between the UE andthe location management function (LMF) as well as between a radio accessnetwork (RAN) and the LMF, etc. The AMF is also referred to herein, moregenerally, as an access and mobility management entity.

The AMF 106 in this illustrative embodiment is operatively coupled tothe Session Management Function (SMF) 110. The Session ManagementFunction provides the essential function for packet data sessionmanagement which enables the user equipment to connect to a data networkusing one of the supported session types, e.g. IPv4, IPv6, IPv4v6,Ethernet, Unstructured, etc. The SMF enables termination of sessionmanagement parts of NAS messages, provides key functionalities forsession establishment, modification and release, including tunnelmaintenance between the user plane function (UPF) and the access network(AN) node. The SMF also enables termination of interfaces towards Policycontrol functions and provides the interface to support transportinguser data via the control plane to enable Control Plane cellularinternet of things (CIoT) 5G system (5GS) optimization feature forinternet of things (IoT) devices.

The AMF 106 in this illustrative embodiment is operatively coupled toother network functions 108, which can include home subscriberfunctions, i.e., one or more functions that are resident in the homenetwork of the subscriber. As shown, some of these functions include theUnified Data Management (UDM) function, as well as an AuthenticationServer Function (AUSF). Other network functions include, but are notlimited to, SMS Function (SMSF), Location Management Function (LMF),Gateway Mobile Location Centre (GMLC), Network Slice Selection Function(NSSF), Network Exposure Function (NEF), Network Repository Function(NRF), Policy Control Function (PCF), Over-the-Air Function (OTAF),Steering of roaming Application Function (SoR-AF) and ApplicationFunction (AF).

One important point to note is that in an SBA communication system, suchas a 5G system, the control plane uses a services model approach inwhich components (NFs) query the NRF to discover and communicate witheach other over application programming interfaces (APIs). The NFservices discovery and authorization method will be described in furtherdetail below.

The access point 104 is also operatively coupled to a User PlaneFunction (UPF) 112. UPF 112 is operatively coupled to a Packet DataNetwork, e.g., Internet 114. As is known in 5G and other communicationnetworks, the user plane (UP) or data plane carries network user trafficwhile the control plane (CP) carries signaling traffic. SMF 110 supportsfunctionalities relating to UP subscriber sessions, e.g., establishment,modification and release of Protocol Data Unit (PDU) sessions. UPF 112supports functionalities to facilitate UP operations, e.g., packetrouting and forwarding, interconnection to the data network (e.g., 114in FIG. 1 ), policy enforcement, and data buffering.

It is to be appreciated that FIG. 1 is a simplified illustration in thatnot all communication links and connections between NFs and other systemelements are illustrated in FIG. 1 . One ordinarily skilled in the artgiven the various 3GPP TSs/TRs will appreciate the various links andconnections not expressly shown or that may otherwise be generalized inFIG. 1 .

Further typical operations and functions of certain network elements arenot described herein in detail when they are not the focus ofillustrative embodiments but can be found in appropriate 3GPP 5Gdocumentation. It is to be appreciated that the particular arrangementof system elements in FIG. 1 is an example only, and other types andarrangements of additional or alternative elements can be used toimplement a communication system in other embodiments. For example, inother embodiments, the system 100 comprises other elements/functions notexpressly shown herein. Also, although only single elements/functionsare shown in the FIG. 1 embodiment, this is for simplicity and clarityof illustration only. A given alternative embodiment may include largernumbers of such system elements, as well as additional or alternativeelements of a type commonly associated with conventional systemimplementations.

It is also to be noted that while FIG. 1 illustrates system elements assingular functional blocks, the various subnetworks that make up the 5Gnetwork are partitioned into so-called network slices. Network slices(network partitions) comprise a series of network function (NF) sets(i.e., function chains) for each corresponding service type usingnetwork function virtualization (NFV) on a common physicalinfrastructure. The network slices are instantiated as needed for agiven service, e.g., eMBB service, massive IoT service, andmission-critical IoT service. A network slice or function is thusinstantiated when an instance of that network slice or function iscreated. In some embodiments, this involves installing or otherwiserunning the network slice or function on one or more host devices of theunderlying physical infrastructure. UE 102 is configured to access oneor more of these services via access point 104 (e.g. gNB). NFs can alsoaccess services of other NFs.

FIG. 2 is a block diagram of user equipment and a network element orfunction configured for providing data transport management in anillustrative embodiment. More particularly, system 200 is showncomprising user equipment 202 and a network element or function 204. Insome embodiments the network element or function 204 represents an AMF.

The user equipment 202 comprises a processor 212 coupled to a memory 216and interface circuitry 210. The processor 212 of the user equipment 202includes a data payload processing module 214 that may be implemented atleast in part in the form of software executed by the processor. Theprocessing module 214 performs data payload or more generally datatransport management described below and elsewhere herein. The memory216 of the user equipment 202 includes a data payload storage module 218that stores data generated or otherwise used during data payloadmanagement operations.

The network element or function 204 comprises a processor 222 coupled toa memory 226 and interface circuitry 220. The processor 222 of thenetwork element or function 204 includes a data payload processingmodule 224 that may be implemented at least in part in the form ofsoftware executed by the processor 222. The processing module 224performs data payload or more generally data transport managementdescribed below and elsewhere herein. The memory 226 of the networkelement or function 204 includes a data payload storage module 228 thatstores data generated or otherwise used during data payload managementoperations.

The respective processors 212 and 222 of the user equipment 202 and thenetwork element or function 204 may comprise, for example,microprocessors, application-specific integrated circuits (ASICs), fieldprogrammable gate arrays (FPGAs), digital signal processors (DSPs) orother types of processing devices or integrated circuits, as well asportions or combinations of such elements. Such integrated circuitdevices, as well as portions or combinations thereof, are examples of“circuitry” as that term is used herein. A wide variety of otherarrangements of hardware and associated software or firmware may be usedin implementing the illustrative embodiments.

The respective memories 216 and 226 of the user equipment 202 and thenetwork element or function 204 may be used to store one or moresoftware programs that are executed by the respective processors 212 and222 to implement at least a portion of the functionality describedherein. For example, data transport management operations and otherfunctionality as described below and otherwise herein may be implementedin a straightforward manner using software code executed by processors212 and 222.

A given one of the memories 216 or 226 may therefore be viewed as anexample of what is more generally referred to herein as a computerprogram product or still more generally as a processor-readable storagemedium that has executable program code embodied therein. Other examplesof processor-readable storage media may include disks or other types ofmagnetic or optical media, in any combination. Illustrative embodimentscan include articles of manufacture comprising such computer programproducts or other processor-readable storage media.

The memory 216 or 226 may more particularly comprise, for example, anelectronic random-access memory (RAM) such as static RAM (SRAM), dynamicRAM (DRAM) or other types of volatile or non-volatile electronic memory.The latter may include, for example, non-volatile memories such as flashmemory, magnetic RAM (MRAM), phase-change RAM (PC-RAM) or ferroelectricRAM (FRAM). The term “memory” as used herein is intended to be broadlyconstrued, and may additionally or alternatively encompass, for example,a read-only memory (ROM), a disk-based memory, or other type of storagedevice, as well as portions or combinations of such devices.

The respective interface circuitries 210 and 220 of the user equipment202 and the network element or function 204 illustratively comprisetransceivers or other communication hardware or firmware that allows theassociated system elements to communicate with one another in the mannerdescribed herein.

It is apparent from FIG. 2 that the user equipment 202 is configured forcommunication with the network element or function 204 and vice-versavia their respective interface circuitries 210 and 220. Thiscommunication involves user equipment 202 sending data to the networkelement or function 204, and the network element or function 204 sendingdata to user equipment 202. However, in alternative embodiments, othernetwork elements may be operatively coupled between, as well as to, theuser equipment 202 and the network element or function 204. The term“data” as used herein is intended to be construed broadly, so as toencompass any type of information that may be sent between userequipment and a base station including, but not limited to, messages,tokens, identifiers, keys, indicators, user data, control data, etc.

It is to be appreciated that the particular arrangement of componentsshown in FIG. 2 is an example only, and numerous alternativeconfigurations are used in other embodiments. For example, userequipment and network elements or functions can be configured toincorporate additional or alternative components and to support othercommunication protocols.

Other elements in a 5G network may each also be configured to includecomponents such as a processor, memory and network interface. Theseelements need not be implemented on separate stand-alone processingplatforms, but could instead, for example, represent differentfunctional portions of a single common processing platform.

Illustrative embodiments provide mechanisms to enable sending andreceiving multiple payload in the same payload container.

Non-Access Stratum (NAS) Transport Procedures

1. General

The purpose of the NAS transport procedures is to provide a transport ofone or multiple payloads between the UE and the AMF. The type of thepayload is identified by the Payload container type information element(IE) and includes one of the following:

-   -   a) a single 5GSM message;    -   b) short message service (SMS);    -   c) an LTE Positioning Protocol (LPP) message;    -   d) a steering of roaming transparent container including        steering of roaming information;    -   e) a UE policy container including UE policy information;    -   f) a UE parameters update transparent container including UE        parameters;    -   g) a location services message; or    -   x) Multiple payloads.

Other types of payloads include a session management message and CIoTuser data. For these as well as payload types a) to g), along with thepayload, the NAS transport procedure may transport the associatedinformation (e.g. Protocol Data Unit (PDU) session information for 5GSystem (5GS) session management (5GSM) message payload).

For payload type x), the Payload container IE consists a list of payloadcontainer entries according to FIG. 6 , where each payload containerentry contains the payload and optional associated information (e.g. PDUsession information for 5GSM message payload). Reference is also made toFIG. 1 a which depicts a NAS message having a header and multiplepayloads, namely, payload 1 in the form of a SM message, payload 2 inthe form of user data, payload 3 in the form of an SMS message, . . .payload n. As shown in FIG. 1 a , the multiple payloads are generated bythe UE and directed over the network to different functions, namely, thetransport of the user data over the control plane to the data network,the session management message to the SMF, the SMS message to the SMSFand other payloads to other network functions.

2. UE-Initiated NAS Transport Procedure

A. General

The purpose of the UE-initiated NAS transport procedure is to provide atransport of:

-   -   a) a single 5GSM message;    -   b) SMS;    -   c) an LTE Positioning Protocol (LPP) message;    -   d) a steering of roaming (SOR) transparent container including        SOR information;    -   e) a UE policy container including UE policy information;    -   f) a UE parameters update transparent container including UE        parameters;    -   g) a location services message; or    -   x) multiple of the above types; and:        -   for a) to g), optional associated payload routing            information from the UE to the AMF in a 5GMM message; and        -   for x), the Payload container IE consists of a list of            payload container entries according to FIG. 6 , where each            of the payload container entries contains the payload and            optional associated information (e.g. PDU session            information for 5GSM message payload). Other types of            messages for which the UE-initiated transport procedure            provides for transport include a session management message            and CIoT user data.

B. UE-Initiated NAS Transport Procedure Initiation

In the connected mode, the UE initiates the NAS transport procedure bysending the UL NAS TRANSPORT message, as shown in FIG. 3 .

In case a) in section 2A, the UE shall:

-   -   a) include the session information specific to the payload (PDU        session ID, old PDU session ID, specific network slice selection        assistance information (S-NSSAI), mapped configured S-NSSAI from        the configured NSSAI for the home public land mobile network        (HPLMN) (if available in roaming scenarios), data network name        (DNN), request type, e.g., session management message request        type, etc.), if available:    -   b) set the Payload container type IE to “N1 SM information”; and    -   c) set the Payload container IE to the 5GSM message.

The UE shall set the PDU session ID IE to the PDU session ID. If an oldPDU session ID is to be included, the UE shall set the Old PDU sessionID IE to the old PDU session ID.

If an S-NSSAI is to be included, the UE shall set the S-NSSAI IE to theS-NSSAI selected for the PDU session from the allowed NSSAI for theserving PLMN, associated with the mapped configured NSSAI for the HPLMN(if available in roaming scenarios).

If a DNN is to be included, the UE shall set the DNN IE to the DNN.If a request type is to be included, the UE shall set the Request typeIE to the request type. The request type is not provided along with 5GSMmessages other than the PDU SESSION ESTABLISHMENT REQUEST message andthe PDU SESSION MODIFICATION REQUEST message.

In an instance in which the UE sends the UL NAS TRANSPORT message to theAMF (see example in FIG. 3 ) and in case b) in section 2A, the UE shall:

-   -   set the Payload container type IE to “SMS”; and    -   set the Payload container IE to the SMS payload.

Based on the UE preferences regarding access selection for mobileoriginated (MO) transmission of SMS over NAS:

-   -   a) when SMS over NAS is preferred to be sent over 3GPP access:        the UE attempts to deliver MO SMS over NAS via the 3GPP access        if the UE is registered over both 3GPP access and non-3GPP        access. If the delivery of SMS over NAS via the 3GPP access is        not available, the UE attempts to deliver MO SMS over NAS via        the non-3GPP access; and    -   b) when SMS over NAS is preferred to be sent over non-3GPP        access: the UE attempts to deliver MO SMS over NAS via the        non-3GPP access if the UE is registered over both 3GPP access        and non-3GPP access. If the delivery of SMS over NAS via the        non-3GPP access is not available, the UE attempts to deliver MO        SMS over NAS via the 3GPP access.

In case c) in section 2A, the UE shall:

-   -   set the Payload container type IE to “LTE Positioning Protocol        (LPP) message container”;    -   set the Payload container IE to the LPP message payload; and    -   set the Additional information IE to the routing information        provided by the upper layer location services application.

In case d) in section 2A, the UE shall:

-   -   set the Payload container type IE to “SOR transparent        container”; and    -   set the Payload container IE to the UE acknowledgement due to        successful reception of steering of roaming information.

In case e) in section 2A, the UE shall:

-   -   set the Payload container type IE to “UE policy container”; and    -   set the contents of the Payload container IE.

In case x) in section 2A, the UE shall:

-   -   set the Payload container type IE to “Multiple payloads”; and    -   set the contents of the Payload container IE as specified in        FIGS. 6-8 . For each payload container entry, the UE shall:        -   i) include the optional IEs in the payload container entry            along with payload container IE as shown in FIG. 7 according            to the following inclusion conditions and the UE:            -   shall include PDU session ID IE when the Payload                container type field of the payload container entry is                set to “N1 SM information”;            -   shall include Old PDU session ID if the UL NAS TRANSPORT                message transports a PDU SESSION ESTABLISHMENT REQUEST                message upon receiving the PDU SESSION MODIFICATION                COMMAND message with the 5GSM cause IE set to                #39“reactivation requested” and the Payload container                type field of the payload container entry is set to “N1                SM information”;            -   shall include Request type when the PDU session ID IE is                included and the Payload container IE contains the PDU                SESSION ESTABLISHMENT REQUEST message or the PDU SESSION                MODIFICATION REQUEST and the Payload container type                field of the payload container entry is set to “N1 SM                information”;            -   may include S-NSSAI when the Request type IE is set to                “initial request” or “existing PDU session” and the                Payload container type field of the payload container                entry is set to “N1 SM information”            -   may include DNN when the Request type IE is set to                “initial request” or “existing PDU session” and the                Payload container type field of the payload container                entry is set to “N1 SM information”; and            -   may include Additional information IE when the Payload                container type field of the payload container entry is                set to “LTE Positioning Protocol (LPP) message                container”; and        -   ii) format the payload container entry as specified in            cases a) to e) of section 2A above.

By way of example and with reference to FIG. 1 a , in an embodiment inwhich the apparatus comprises the user equipment, the apparatus iscaused to generate a payload container information element comprisingtwo or more payloads by bundling the two or more payloads generated bydifferent applications of the user equipment, such as by the SM layer,the LCS layer, the SMS layer, the USIM, etc., along with routing orsession information into the payload container information element. Theapparatus is also caused to encapsulate the payload containerinformation element comprising the two or more payload entries in anon-access stratum message. Further, the apparatus of this exampleembodiment is caused to send the payload container information elementby causing the non-access stratum message encapsulating the payloadcontainer information element to be sent to a mobility managementfunction, such as an AMF.

C. UE-Initiated NAS Transport of Messages Accepted by the Network

Upon reception of a UL NAS TRANSPORT message, if the Payload containertype IE is set to:

-   -   a) “N1 SM information”, the AMF looks up a PDU session routing        context for:        -   1) the UE and the PDU session ID IE in case the Old PDU            session ID IE is not included other than the instance in            which the Old PDU session ID IE is not included in the            uplink (UL) NAS TRANSPORT message and the AMF has received a            reallocation requested indication from the SMF, in which            instance the AMF needs to ignore the reallocation requested            indication, and:            -   i) if the AMF has a PDU session routing context for the                PDU session ID and the UE, and the Request type IE is                either not included or is included but set to other                value than “initial request”, “existing PDU session”,                “initial emergency request” and “existing emergency PDU                session”, the AMF shall forward the 5GSM message, and                the PDU session ID IE towards the SMF identified by the                SMF ID of the PDU session routing context;            -   ii) if the AMF has a PDU session routing context for the                PDU session ID and the UE, the PDU session routing                context indicates that the PDU session is not an                emergency PDU session, the Request type IE is included                and is set to “existing PDU session”, and the S-NSSAI                associated with the PDU session identified by the PDU                session ID is allowed for the target access type, the                AMF shall forward the 5GSM message, the PDU session ID,                the S-NSSAI, the mapped configured S-NSSAI from the                configured NSSAI for the HPLMN (if available in roaming                scenarios), the DNN (if received) and the request type                towards the SMF identified by the SMF ID of the PDU                session routing context;            -   iii) if the AMF does not have a PDU session routing                context for the PDU session ID and the UE, and the                Request type IE is included and is set to “initial                request”:                -   A) the AMF shall select an SMF with the following                    handlings:                -   If the S-NSSAI IE is not included and the user's                    subscription context obtained from UDM:                -    contains one default S-NSSAI, the AMF shall use the                    default S-NSSAI as the S-NSSAI;                -    contains two or more default S-NSSAIs, the AMF                    shall use one of the default S-NSSAIs selected by                    operator policy as the S-NSSAI; and                -    does not contain a default S-NSSAI, the AMF shall                    use an S-NSSAI selected based on operator policy as                    the S-NSSAI.

If the DNN IE is not included, and the user's subscription contextobtained from UDM:

-   -   contains the default DNN for the S-NSSAI, the AMF shall use the        default DNN as the DNN; and    -   does not contain the default DNN for the S-NSSAI, the AMF shall        use a locally configured DNN as the DNN; and

If the DNN is a LADN DNN, the AMF shall determine the UE presence in thelocal area data network (LADN) service area; and

-   -   B) if the SMF selection is successful:        -   the AMF shall store a PDU session routing context for the            PDU session ID and the UE, shall set the SMF ID in the            stored PDU session routing context to the SMF ID            corresponding to the DNN in the user's subscription context            obtained from the UDM; and        -   the AMF shall forward the 5GSM message, the PDU session ID,            the S-NSSAI, the mapped configured S-NSSAI from the            configured NSSAI for the HPLMN (if available in roaming            scenarios), the DNN, the request type and UE presence in            LADN service area (if DNN received corresponds to an LADN            DNN) towards the SMF identified by the SMF ID of the PDU            session routing context;    -   iv) if the AMF does not have a PDU session routing context for        the PDU session ID and the UE, the Request type IE is included        and is set to “existing PDU session”, and the user's        subscription context obtained from the UDM contains an SMF ID        associated with:    -   A) the PDU session ID matching the PDU session ID received from        the UE, if any; or    -   B) the DNN matching the DNN received from the UE, otherwise;    -   such that the SMF ID includes a PLMN identity corresponding to        the UE's HPLMN or the current PLMN, then:    -   A) the AMF shall store a PDU session routing context for the PDU        session ID and the UE, shall set the SMF ID in the stored PDU        session routing context to the SMF ID contained in the user's        subscription context obtained from the UDM; and    -   B) the AMF shall forward the 5GSM message, the PDU session ID,        the S-NSSAI, the mapped configured S-NSSAI from the configured        NSSAI for the HPLMN (if available in roaming scenarios), the DNN        (if received) and the request type towards the SMF identified by        the SMF ID of the PDU session routing context;    -   v) if the AMF does not have a PDU session routing context for        the PDU session ID and the UE, the Request type IE is included        and is set to “initial emergency request”, and the AMF does not        have a PDU session routing context for another PDU session ID of        the UE indicating that the PDU session is an emergency PDU        session:    -   A) the AMF shall select an SMF. The AMF shall use the emergency        DNN from the AMF emergency configuration data as the DNN, if        configured. The AMF shall derive the SMF from the emergency DNN        or use the statically configured SMF from the AMF emergency        configuration data, if configured; and    -   B) if the SMF selection is successful:        -   the AMF shall store a PDU session routing context for the            PDU session ID and the UE, shall set the SMF ID in the            stored PDU session routing context to the SMF ID of the            selected SMF, and shall store an indication that the PDU            session is an emergency PDU session in the stored PDU            session routing context; and        -   the AMF shall forward the 5GSM message, the PDU session ID,            the S-NSSAI (if configured in the AMF emergency            configuration data), the DNN (if configured in the AMF            emergency configuration data), and the request type towards            the SMF identified by the SMF ID of the PDU session routing            context; and    -   vi) if the AMF does not have a PDU session routing context for        the PDU session ID and the UE, the Request type IE is included        and is set to “initial emergency request”, and the AMF has a PDU        session routing context indicating that the PDU session is an        emergency PDU session for another PDU session ID of the UE:    -   A) the AMF shall store a PDU session routing context for the PDU        session ID and the UE and shall set the SMF ID in the stored PDU        session routing context to the SMF ID of the PDU session routing        context for the other PDU session ID of the UE; and    -   B) the AMF shall forward the 5GSM message, the PDU session ID,        the S-NSSAI (if configured in the AMF emergency configuration        data), the DNN (if configured in the AMF emergency configuration        data) and the request type towards the SMF identified by the SMF        ID of the PDU session routing context; or    -   vii) if the AMF has a PDU session routing context for the PDU        session ID and the UE, the PDU session routing context indicates        that the PDU session is an emergency PDU session, and the        Request type IE is included and is set to “existing emergency        PDU session”, the AMF shall forward the 5GSM message, the PDU        session ID, the S-NSSAI (if configured in the AMF emergency        configuration data), the DNN (if configured in the AMF emergency        configuration data), and the request type towards the SMF        identified by the SMF ID of the PDU session routing context; and    -   viii) if the AMF does not have a PDU session routing context for        the PDU session ID and the UE, the Request type IE is included        and is set to “existing emergency PDU session”, and the user's        subscription context obtained from the UDM contains an SMF ID        for the DNN matching the DNN received from the UE such that the        SMF ID includes a PLMN identity corresponding to the current        PLMN, then:    -   A) the AMF shall store a PDU session routing context for the PDU        session ID and the UE, shall set the SMF ID in the stored PDU        session routing context to the SMF ID contained in the user's        subscription context obtained from the UDM; and    -   B) the AMF shall forward the 5GSM message, the PDU session ID,        the S-NSSAI (if configured in the AMF emergency configuration        data), the DNN (if configured in the AMF emergency configuration        data), and the request type towards the SMF identified by the        SMF ID of the PDU session routing context; or    -   2) the UE and the Old PDU session ID IE in case the Old PDU        session ID IE is included, and:    -   i) the AMF has a PDU session routing context for the old PDU        session ID and the UE and does not have a PDU session routing        context for the PDU session ID and the UE, the Request type IE        is included and is set to “initial request”, and the AMF        received a reallocation requested indication from the SMF        indicating that the SMF is to be reused, the AMF shall store a        PDU session routing context for the PDU session ID and the UE,        set the SMF ID in the stored PDU session routing context to the        SMF ID of the PDU session routing context for the old PDU        session ID and the UE. If the DNN is a LADN DNN, the AMF shall        determine the UE presence in the LADN service area. The AMF        shall forward the 5GSM message, the PDU session ID, the old PDU        session ID, the S-NSSAI (if received), the mapped configured        S-NSSAI from the configured NSSAI for the HPLMN (if available in        roaming scenarios), the DNN, the request type and UE presence in        LADN service area (if DNN received corresponds to an LADN DNN)        towards the SMF identified by the SMF ID of the PDU session        routing context;    -   ii) the AMF has a PDU session routing context for the old PDU        session ID and the UE and does not have a PDU session routing        context for the PDU session ID and the UE, the Request type IE        is included and is set to “initial request”, and the AMF        received a reallocation requested indication from the SMF        indicating that the SMF is to be reallocated:    -   A) the AMF shall select an SMF with the following handling;    -   If the S-NSSAI IE is not included and the user's subscription        context obtained from UDM:        -   contains one default S-NSSAI, the AMF shall use the default            S-NSSAI as the S-NSSAI;        -   contains two or more default S-NSSAIs, the AMF shall use one            of the default S-NSSAIs selected by operator policy as the            S-NSSAI; and        -   does not contain a default S-NSSAI, the AMF shall use an            S-NSSAI selected based on operator policy as the S-NSSAI.

If the DNN is a LADN DNN, the AMF shall determine the UE presence in theLADN service area; and

-   -   B) if the SMF selection is successful:        -   the AMF shall store a PDU session routing context for the            PDU session ID and the UE and set the SMF ID of the PDU            session routing context to the SMF ID of the selected SMF;            and        -   the AMF shall forward the 5GSM message, the PDU session ID,            the old PDU session ID, the S-NSSAI, the mapped configured            S-NSSAI from the configured NSSAI for the HPLMN (if            available in roaming scenarios), the DNN, the request type            and UE presence in the LADN service area (if DNN received            corresponds to an LADN DNN) towards the SMF identified by            the SMF ID of the PDU session routing context for the PDU            session ID and the UE;    -   b) “SMS”, the AMF shall forward the content of the Payload        container IE to the SMSF associated with the UE;    -   c) “LTE Positioning Protocol (LPP) message container”, the AMF        shall forward the content of the Payload container IE to the        location management function (LMF) associated with the routing        information included in the Additional information IE of the UL        NAS TRANSPORT message;    -   d) “SOR transparent container”, the AMF shall forward the        content of the Payload container IE to the UDM;    -   e) “UE policy container”, the AMF shall forward the content of        the Payload container IE to the PCF; and    -   x) “Multiple payloads”, the AMF shall first decode the content        of the Payload container IE into individual payloads as        specified in FIGS. 6-8 . For each payload container entry, the        AMF shall:        -   i) decode optional IEs in the payload container entry and            payload container field according to FIG. 7 ; and        -   ii) apply the same handling as specified in cases (a)-(e)            above according to the payload container type within each            payload container entry.

By way of example and with reference to FIG. 1 a , in an embodiment inwhich the apparatus comprises a mobility management function (MMF), suchas an AMF, the apparatus is caused to receive two or more messagescontaining payloads that are generated by one or more network functions,e.g., SMF, SMSF, PCF, LMF, GMLC, UDM, etc., and provided to the MMF viaan MMF service based interface, such as to the AMF via an AMF servicebased interface and to extract the payloads along from the two or morereceived messages from the one or more network functions. In thisexample embodiment, the apparatus is caused to generate the payloadcontainer information element by bundling the two or more extractedpayloads along with routing or session information into the payloadcontainer information element and the apparatus is also caused toencapsulate the payload container information element comprising the twoor more payload entries into a non-access stratum message. In thisexample embodiment, the apparatus is further caused to send the payloadcontainer information element by causing the payload containerinformation element to be sent to the user equipment as part of thenon-access stratum transport procedure.

3. Network-Initiated NAS Transport Procedure

A. General

The purpose of the network-initiated NAS transport procedure is toprovide a transport of:

-   -   a) a single 5GSM message;    -   b) SMS;    -   c) an LPP message;    -   d) an SOR transparent container;    -   e) a single uplink 5GSM message which was not forwarded due to        routing failure;    -   f) a single uplink 5GSM message which was not forwarded due to        congestion control;    -   g) a UE policy container;    -   h) a single uplink 5GSM message which was not forwarded, because        the public land mobile network's (PLMN′)s maximum number of PDU        sessions has been reached; or    -   y) multiple of the above types.        from the AMF to the UE in a 5GMM message. Reference is also made        to FIG. 1 b which depicts payloads from different network        functions being bundled into a NAS message and sent to the UE.        The resulting NAS message has a header and multiple payloads,        namely, payload 1 in the form of a SM message, payload 2 in the        form of user data, payload 3 in the form of an SMS message, . .        . payload n. As shown in FIG. 1 b , the multiple payloads are        generated by different network functions, such as the data        network with respect to the user data, the SMF with respect to        the SM message, the SMSF with respect to the SMS message and the        like. The multiple payloads are bundled into a single NAS        message and transmitted to the UE.

B. Network-Initiated NAS Transport Procedure Initiation

In connected mode, the AMF initiates the NAS transport procedure bysending the downlink (DL) NAS TRANSPORT message, as shown in FIG. 4 .

In case a) in section 3A, i.e. upon reception from an SMF of a 5GSMmessage without an N1 SM delivery skip allowed indication for a UE or a5GSM message with an N1 SM delivery skip allowed indication for a UE inthe 5GMM-CONNECTED mode, the AMF shall:

-   -   a) include the PDU session information (PDU session ID) in the        PDU session ID IE;    -   b) set the Payload container type IE to “N1 SM information”; and    -   c) set the Payload container IE to the 5GSM message.

In case b) in section 3A, i.e. upon reception from a short messageservice function (SMSF) of an SMS payload, the AMF shall:

-   -   a) set the Payload container type IE to “SMS”;    -   b) set the Payload container IE to the SMS payload; and    -   c) select the access type to deliver the DL NAS TRANSPORT        message as follows in case the access type selection is        required:        -   1) if the UE to receive the DL NAS TRANSPORT message is            registered to the network via both 3GPP access and non-3GPP            access, the 5^(th) generation mobility management (5GMM)            context of the UE indicates that SMS over NAS is allowed,            the UE is in mobile initiated connection only (MICO) mode,            and the UE is in 5GMM-IDLE mode for 3GPP access and in            5GMM-CONNECTED mode for non-3GPP access, then the AMF            selects non-3GPP access. Otherwise, the AMF selects either            3GPP access or non-3GPP access.

If the delivery of the DL NAS TRANSPORT message over 3GPP access hasfailed, the AMF may re-send the DL NAS TRANSPORT message over thenon-3GPP access.

If the delivery of the DL NAS TRANSPORT message over non-3GPP access hasfailed, the AMF may re-send the DL NAS TRANSPORT message over the 3GPPaccess; and

-   -   2) otherwise, the AMF selects 3GPP access.        In this case, the AMF selects an access type between 3GPP access        and non-3GPP access based on operator policy.

In case c) in section 3A, i.e. upon reception from an LMF of an LPPmessage payload, the AMF shall:

-   -   a) set the Payload container type IE to “LTE Positioning        Protocol (LPP) message container”;    -   b) set the Payload container IE to the LPP message payload        received from the LMF; and    -   c) set the Additional information IE to the routing information        associated with the LMF from which the LPP message was received.

In case d) in section 3A, i.e. upon reception of a steering of roaminginformation from the UDM to be forwarded to the UE, the AMF shall:

-   -   a) set the Payload container type IE to “SOR transparent        container”; and    -   b) set the Payload container IE to the steering of roaming        information received from the UDM.

In case e) in section 3A, i.e. upon sending a single uplink 5GSM messagewhich was not forwarded due to routing failure, the AMF shall:

-   -   a) include the PDU session ID in the PDU session ID IE;    -   b) set the Payload container type IE to “N1 SM information”;    -   c) set the Payload container IE to the 5GSM message which was        not forwarded; and    -   d) set the 5GMM cause IE to the 5GMM cause #90 “payload was not        forwarded” or 5GMM cause #91 “DNN not supported with no slice or        DNN not supported in specific slice”. The AMF sets the 5GMM        cause IE to the 5GMM cause #91 “DNN not supported with no slice        or DNN not supported in specific slice”, if the 5GSM message        could not be forwarded since SMF selection fails due to the DNN        not being supported in the slice identified by the S-NSSAI used        by the AMF.

In case f) in section 3A, i.e. upon sending a single uplink 5GSM messagewhich was not forwarded due to congestion control, the AMF shall:

-   -   a) include the PDU session ID in the PDU session ID IE;    -   b) set the Payload container type IE to “N1 SM information”;    -   c) set the Payload container IE to the 5GSM message which was        not forwarded;    -   d) set the 5GMM cause IE to the 5GMM cause #22 “Congestion”, the        5GMM cause #67 “insufficient resources for specific slice and        DNN” or the 5GMM cause #69 “insufficient resources for specific        slice”; and    -   e) include the Back-off timer value IE.

In case g) in section 3A, i.e. upon reception of a UE policy containerfrom the PCF to be forwarded to the UE, the AMF shall:

-   -   a) set the Payload container type IE to “UE policy container”;        and    -   b) set the Payload container IE to the UE policy container        received from the PCF.

In case h) in section 3A, i.e. upon sending a single uplink 5GSM messagewhich was not forwarded, because the PLMN's maximum number of PDUsessions has been reached, the AMF shall:

-   -   a) include the PDU session ID in the PDU session ID IE;    -   b) set the Payload container type IE to “N1 SM information”;    -   c) set the Payload container IE to the 5GSM message which was        not forwarded; and    -   d) set the 5GMM cause IE to the 5GMM cause #65 “maximum number        of PDU sessions reached”.

In case y) in section 3A, the AMF shall:

-   -   a) set the Payload container type IE to “Multiple payloads”;    -   b) set the contents of the Payload container IE as specified in        FIGS. 6-8 . For each payload container entry, the AMF shall:        -   i) include the optional IEs in the payload container entry            along with payload container field as shown in FIG. 7            according to the following inclusion conditions:            -   include PDU session ID IE when the payload container                type field of the payload container entry is set to “N1                SM information”;            -   include Additional information IE when the payload                container type field of the payload container entry is                set to “LTE Positioning Protocol (LPP) message                container”;            -   include 5GMM cause when the payload container field of                the payload container entry contains an uplink payload                which was not forwarded and the payload container type                field of the payload container entry is set to “N1 SM                information”; and            -   include Back-off timer value when the payload container                field of the payload container entry contains an uplink                5GSM message which was not forwarded due to DNN based                congestion control, S-NSSAI and DNN based congestion                control or S-NSSAI only based congestion control and the                payload container type field of the payload container                entry is set to “N1 SM information”; and        -   ii) format the payload container field of the payload            container entry as specified in cases a) to h) above.

By way of example and with reference to FIG. 1 b , in an embodiment inwhich the apparatus comprises the user equipment, the apparatus iscaused to receive the payload container information element by receivinga non-access stratum (NAS) message with the payload containerinformation element containing the two or more payloads. The apparatusis also caused to decode the two or more payload entries by extractingthe two or more payloads from the received NAS message. In this exampleembodiment, the apparatus is further caused to determine a destinationapplication in the user equipment for a respective payload based uponthe identification of the payload container type and informationassociated with the respective payload in the corresponding payloadentry and to cause each respective payload is sent to a differentapplication in the user equipment, such as applicants of the SM layer,the LCS entity, the SMS layer, the USIM, etc.

C. Network-Initiated NAS Transport of Messages

Upon reception of a DL NAS TRANSPORT message, if the Payload containertype IE is set to:

-   -   a) “N1 SM information” and the 5GMM cause IE is not included in        the DL NAS TRANSPORT message, the 5GSM message in the Payload        container IE and the PDU session ID are handled in the 5GSM        procedures;    -   b) “SMS”, the UE shall forward the content of the Payload        container IE to the SMS stack entity;    -   c) “LTE Positioning Protocol (LPP) message container”, the UE        shall forward the content of the Payload container IE and the        routing information included in the Additional information IE to        the upper layer location services application;    -   d) “SOR transparent container” and if the payload container IE:        -   1) successfully passes the integrity check, and indicates a            list of preferred PLMN/access technology combinations is            provided and the list type indicates:            -   i) “PLMN ID and access technology list”, then the ME                shall replace the highest priority entries in the                “Operator Controlled PLMN Selector with Access                Technology” list stored in the ME and shall proceed with                the behaviour as specified in 3GPP TS 23.122 [5] annex                C; or            -   ii) “secure packet”, then the ME shall behave as if a                SMS is received with protocol identifier set to SIM data                download, data coding scheme set to class 2 message and                SMS payload as secure packet contents of SOR transparent                container IE. The SMS payload is forwarded to UICC as                specified in 3GPP TS 23.040 [4A] and the ME shall                proceed with the behaviour as specified in 3GPP TS                23.122 [5] annex C; or        -   2) does not successfully pass the integrity check (see 3GPP            TS 33.501 [24]) then the UE shall proceed with the behaviour            as specified in 3GPP TS 23.122 [5] annex C.    -   e) “N1 SM information” and the 5GMM cause IE is set to the 5GMM        cause #90 “payload was not forwarded” in the DL NAS TRANSPORT        message, the UE passes to the 5GSM sublayer an indication that        the 5GSM message was not forwarded due to routing failure along        with the 5GSM message from the Payload container IE of the DL        NAS TRANSPORT message;    -   f) “N1 SM information” and the 5GMM cause IE is set to the 5GMM        cause #91 “DNN not supported with no slice or DNN not supported        in specific slice” in the DL NAS TRANSPORT message, the UE        passes to the 5GSM sublayer an indication that the 5GSM message        was not forwarded due to the DNN not being supported in a slice        along with the 5GSM message from the Payload container IE of the        DL NAS TRANSPORT message;    -   g) “N1 SM information” and:        -   the 5GMM cause IE is set to the 5GMM cause #22 “Congestion”,            the UE passes to the 5GSM sublayer an indication that the            5GSM message was not forwarded due to DNN based congestion            control along with the 5GSM message from the Payload            container IE of the DL NAS TRANSPORT message, and the time            value from the Back-off timer value IE;        -   the 5GMM cause IE is set to the 5GMM cause #65 “maximum            number of PDU sessions reached”, the UE passes to the 5GSM            sublayer an indication that the 5GSM message was not            forwarded because the PLMN's maximum number of PDU sessions            has been reached, along with the 5GSM message from the            Payload container IE of the DL NAS TRANSPORT message;        -   the 5GMM cause IE is set to the 5GMM cause #67 “insufficient            resources for specific slice and DNN”, the UE passes to the            5GSM sublayer an indication that the 5GSM message was not            forwarded due to S-NSSAI and DNN based congestion control            along with the 5GSM message from the Payload container IE of            the DL NAS TRANSPORT message, and the time value from the            Back-off timer value IE; or        -   the 5GMM cause IE is set to the 5GMM cause #69 “insufficient            resources for specific slice”, the UE passes to the 5GSM            sublayer an indication that the 5GSM message was not            forwarded due to S-NSSAI only based congestion control along            with the 5GSM message from the Payload container IE of the            DL NAS TRANSPORT message, and the time value from the            Back-off timer value IE; and    -   h) “UE policy container”, the UE policy container in the Payload        container IE is handled in the UE policy delivery procedures;    -   y) “Multiple payloads”, the UE shall first decode the content of        the Payload container IE into individual payload container        entries as specified in FIGS. 6-8 . For each payload container        entry, the UE shall:        -   i) decode optional IEs in the payload container entry and            payload container field according to FIG. 7 ; and        -   ii) apply the same handling as specified in cases above            according to the payload container type field within each            payload container entry.

By way of example and with reference to FIG. 1 b , in an embodiment inwhich the apparatus comprises a mobility management function (MMF), suchas an AMF, the apparatus is caused to receive the payload containerinformation element by receiving a non-access stratum (NAS) message withthe payload container information element comprising the two or morepayloads. The apparatus is also caused to decode the two or more payloadentries by extracting the two or more payloads from the received NASmessage. In this example embodiment, the apparatus is further caused todetermine a destination network function for a respective payload basedupon the identification of the payload container type and informationassociated with the respective payload in the corresponding payloadentry, encapsulate the respective payloads into separate messages andcause the separate messages to be sent to corresponding destinationnetwork functions, e.g., SMF, SMSF, PCF, LMF, GMLC, UDM, etc.

4. Payload Container

The purpose of the Payload container information element is to transportone or multiple payloads. If multiple payloads are transported, theassociated information of each payload are also transported togetherwith the payload.

The Payload container information element is coded as shown in FIGS. 5-8and as described below.

The Payload container is a type 6 information element with a minimumlength of 4 octets and a maximum length of 65538 octets.

The Payload Container Contents (Octet 4 to Octet n); Max Value of 65535Octets

If the payload container type is a SOR transparent container and isincluded in the DL NAS TRANSPORT message, the payload container contentsare coded the same way as the contents of the SOR transparent containerIE for SOR data type with value “0” except that the first three octetsare not included.

If the payload container type is a SOR transparent container and isincluded in the UL NAS TRANSPORT message, the payload container contentsare coded the same way as the contents of the SOR transparent containerIE for SOR data type with value “1” except that the first three octetsare not included.

If the payload container type is multiple payloads, the number ofentries field represents the total number of payload container entries,and the payload container contents field is coded as a list of payloadcontainer entry according to FIG. 6 , with each payload container entrybeing coded according to FIGS. 7 and 8 .

The coding of Payload container contents is dependent on the particularapplication.

Payload Container Entry

For each Payload container entry, the Payload container type representsthe payload type and the number of optional IEs field represents thetotal number of optional IEs associated with the payload in Payloadcontainer entry.

Optional IE

Each optional IE is coded according to FIG. 8 .

Type of Optional IE (Octet xi+2)

This field contains the IEI of the optional IE entry and is 1 octet inlength.

The following table lists IEI and optional IE names:

IEI Optional IE name 70 PDU session ID 24 Additional information 58 5GMMcause 37 Back-off timer value 61 Old PDU session ID 8- Request type 22S-NSSAI 25 DNN

The following optional IEs can be included in the payload containerentry along with payload container field as shown in FIG. 7 duringnetwork-initiated NAS transport procedure according to the followinginclusion conditions:

PDU Session ID

The AMF shall include this IE when the Payload container type IE of thepayload container entry is set to “N1 SM information”.

Additional Information

The AMF may include this IE when the Payload container type IE of thepayload container entry is set to “LTE Positioning Protocol (LPP)message container”.

5GMM Cause

The AMF shall include this IE when the Payload container IE of thepayload container entry contains an uplink payload which was notforwarded.

Back-Off Timer Value

The AMF shall include this IE when the Payload container IE of thepayload container entry contains an uplink 5GSM message which was notforwarded due to DNN based congestion control, S-NSSAI and DNN basedcongestion control or S-NSSAI only based congestion control.

The following optional IEs can be included in the payload containerentry along with payload container IE as shown in FIG. 7 duringUE-initiated NAS transport procedure according to the followinginclusion conditions:

PDU Session ID

The UE shall include this IE when the Payload container type IE is setto “N1 SM information”.

Old PDU Session ID

The UE shall include this IE if the UL NAS TRANSPORT message transportsa PDU SESSION ESTABLISHMENT REQUEST message upon receiving the PDUSESSION MODIFICATION COMMAND message with the 5GSM cause IE set to #39“reactivation requested”.

Request Type

The UE shall include this IE when the PDU session ID IE is included andthe Payload container IE contains the PDU SESSION ESTABLISHMENT REQUESTmessage or the PDU SESSION MODIFICATION REQUEST.

S-NSSAI

The UE may include this IE when the Request type IE is set to “initialrequest” or “existing PDU session”.

DNN

The UE may include this IE when the Request type IE is set to “initialrequest” or “existing PDU session”.

Additional Information

The UE may include this IE when the Payload container type IE is set to“LTE Positioning Protocol (LPP) message container”.

5. Payload Container Type

The purpose of the Payload container type information element indicatestype of payload included in the payload container information element.

The Payload container information element is coded as shown in FIG. 9 .

The Payload container is a type 1 information element with a length ofhalf octet.

The Payload container type value (octet 1, bit 1 to bit 4) is shown inthe following table:

Bits 4 3 2 1 0 0 0 1 N1 SM information 0 0 1 0 SMS 0 0 1 1 LTEPositioning Protocol (LPP) message container 0 1 0 0 SOR transparentcontainer 0 1 0 1 UE policy container . . . 1 1 1 1 Multiple payloads

All other values are reserved. The value “Multiple payloads” is usedwhen the Payload container contents in FIG. 5 contains multiple payloadsformatted as shown in FIG. 6 .

The particular processing operations and other system functionalitydescribed in conjunction with the diagrams herein are presented by wayof illustrative example only, and should not be construed as limitingthe scope of the disclosure in any way. Alternative embodiments can useother types of processing operations and messaging protocols. Forexample, the ordering of the steps may be varied in other embodiments,or certain steps may be performed at least in part concurrently with oneanother rather than serially. Also, one or more of the steps may berepeated periodically, or multiple instances of the methods can beperformed in parallel with one another.

It should therefore again be emphasized that the various embodimentsdescribed herein are presented by way of illustrative example only andshould not be construed as limiting the scope of the claims. Forexample, alternative embodiments can utilize different communicationsystem configurations, user equipment configurations, base stationconfigurations, key pair provisioning and usage processes, messagingprotocols and message formats than those described above in the contextof the illustrative embodiments. These and numerous other alternativeembodiments within the scope of the appended claims will be readilyapparent to those skilled in the art.

1. An apparatus comprising: at least one processor; and a memory storingone or more software programs executed by the at least one processor tocause the apparatus to: generate a payload container information elementand a payload container type information element, wherein the payloadcontainer information element comprises two or more payload entries,wherein the payload container information element comprises payloadcontainer contents, the payload container contents comprising anindication of a number of entries and a plurality of payload containerentries including the two or more payload entries, and wherein thepayload container type information element comprises an identificationof a payload type, the identification of the payload type comprising anidentification of multiple payloads to designate inclusion of the two ormore payload entries in the payload container information element; andcause the payload container information element and the payloadcontainer type information element to be sent as part of a non-accessstratum transport procedure to least one network element in acommunication system.
 2. The apparatus of claim 1, wherein the apparatuscomprises a user equipment.
 3. The apparatus of claim 2, wherein theapparatus is caused to generate the payload container informationelement comprising the two or more payloads by bundling the two or morepayloads generated by different applications along with routing orsession information into the payload container information element,wherein the apparatus is also caused to encapsulate the payloadcontainer information element comprising the two or more payload entriesin a non-access stratum message, and wherein the apparatus is caused tosend the payload container information element by causing the non-accessstratum message encapsulating the payload container information elementto be sent to a mobility management function.
 4. The apparatus of claim1, wherein a respective one of the plurality of payload containerentries comprises an indication of a length of the respective payloadcontainer entry, an indication of a payload container type and payloadcontainer entry contents of the respective payload container entry. 5.The apparatus of claim 4, wherein each of at least a portion of the twoor more payload entries comprises information associated with thepayload container entry contents corresponding to the respective payloadentry.
 6. The apparatus of claim 5, wherein the information associatedwith the payload container entry contents corresponding to therespective payload entry comprises session information specific to thepayload entry.
 7. The apparatus of claim 6, wherein each of the two ormore payload entries comprises one of the following types: a Sessionmanagement message, a short message service (SMS) message, a locationpositioning protocol (LPP) message, Steering of roaming information,user equipment (UE) policy information, UE parameters, Location servicemessage or cellular internet of things (CIoT) user data.
 8. Theapparatus of claim 6, wherein the session information specific to thepayload entry comprises one of the following: a Session managementmessage request type, a packet data unit (PDU) session ID, a Datanetwork name or Network Slice Selection Assistance Information(S-NSSAI).
 9. A method comprising: generating a payload containerinformation element and a payload container type information element,wherein the payload container information element comprises two or morepayload entries, wherein the payload container information elementcomprises payload container contents, and wherein the payload containercontents comprise an indication of a number of entries and a pluralityof payload container entries including the two or more payload entries,and wherein the payload container type information element comprises anidentification of a payload type, the identification of the payload typecomprising an identification of multiple payloads to designate inclusionof the two or more payload entries in the payload container informationelement; and causing the payload container information element and thepayload container type information element be sent as part of anon-access stratum transport procedure to at least one network elementof a communication system.
 10. The method of claim 9, wherein the methodis performed by a user equipment.
 11. The method of claim 10, whereingenerating the payload container information element comprising the twoor more payloads comprises bundling the two or more payloads generatedby different applications along with routing or session information intothe payload container information element, wherein the method furthercomprises encapsulating the payload container information elementcomprising the two or more payload entries in a non-access stratummessage, and wherein causing the payload container information elementto be sent comprises causing the non-access stratum messageencapsulating the payload container information element to be sent to amobility management function.
 12. The method of claim 9, wherein arespective one of the plurality of payload container entries comprisesan indication of a length of the respective payload container entry, anindication of a payload container type and payload container entrycontents of the respective payload container entry.
 13. The method ofclaim 12, wherein each of at least a portion of the two or more payloadentries comprises information associated with the payload containerentry contents corresponding to the respective payload entry.
 14. Themethod of claim 13, wherein the information associated with the payloadcontainer entry contents corresponding to the respective payload entrycomprises session information specific to the payload entry.
 15. Anapparatus comprising: at least one processor; and a memory storing oneor more software programs executed by the at least one processor tocause the apparatus to: receive a payload container information elementand a payload container type information element, wherein the payloadcontainer information element comprises two or more payload entries aspart of a non-access stratum transport procedure from at least onenetwork element of a communication system, wherein the payload containerinformation element comprises payload container contents, the payloadcontainer contents comprising an indication of a number of entries and aplurality of payload container entries including the two or more payloadentries, and wherein the payload container type information elementcomprises an identification of a payload type, the identification of thepayload type comprising an identification of multiple payloads todesignate inclusion of the two or more payload entries in the payloadcontainer information element; and decode the two or more payloadentries of the payload container information element into two or moreindividual payloads.
 16. The apparatus of claim 15, wherein theapparatus comprises a user equipment.
 17. The apparatus of claim 16,wherein the apparatus is caused to receive the payload containerinformation element and the payload container type information elementby receiving a non-access stratum (NAS) message with the payloadcontainer information element containing the two or more payloads,wherein the apparatus is caused to decode the two or more payloadentries by extracting the two or more payloads from the received NASmessage, and wherein the apparatus is further caused to: determine adestination application in the user equipment for a respective payloadbased upon the identification of the payload type and informationassociated with the respective payload in the corresponding payloadentry; and cause each respective payload is sent to a differentapplication in the user equipment.
 18. The apparatus of claim 15,wherein a respective one of the plurality of payload container entriescomprises an indication of a length of the respective payload containerentry, an indication of a payload container type and payload containerentry contents of the respective payload container entry.
 19. Theapparatus of claim 18, wherein each of at least a portion of the two ormore payload entries comprises information associated with the payloadcontainer entry contents corresponding to the respective payload entry.20. The apparatus of claim 19, wherein the information associated withthe payload container entry contents corresponding to the respectivepayload entry comprises session information specific to the payloadentry.